Treadmill

ABSTRACT

A treadmill includes a frame, two front wheels supported on the frame, two rear wheels supported on the frame, a caterpillar track wound on the front and rear wheels, and two rolling units each connected to a related one of two edges of the caterpillar track. Each of the front wheels includes a periphery and a plurality of recesses defined in the periphery. Each of the rolling units includes rollers each of which can be received in a related one of recesses.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a treadmill and, more particularly, toa treadmill including a caterpillar track and an apparatus for stablydriving the caterpillar track.

2. Related Prior Art

In a modern society, many people work and spend long hours in officesevery day. These people must exercise their bodies to remain physicallyhealthy. There are various exercise machines to facilitate these peopleto exercise various muscles of their bodies.

Such exercise machines include pedaling exercise machines, steppers,oval-movement exercise machines, treadmills and multi-functionalexercise machines. Treadmills are the most popular exercise machinesamong them. A typical electric treadmill includes a frame, an activeroller supported on the frame, an idle roller also supported on theframe, a belt wound on the active and idle rollers, and a motor fordriving the active roller. Thus, the motor drives the belt through theactive roller. The periphery of the active roller is smooth andsometimes slides relative to an internal surface of the belt so that theactive roller fails to drive the belt. That is, the driving of the beltby the motor through the active roller is unstable.

The present invention is therefore intended to obviate or at leastalleviate the problems encountered in prior art.

SUMMARY OF INVENTION

It is the primary objective of the present invention to provide atreadmill with a stably driven caterpillar track.

To achieve the foregoing objective, the treadmill further includes aframe, two front wheels supported on the frame, two rear wheelssupported on the frame, and two rolling units each connected to arelated one of two edges of the caterpillar track. The caterpillar trackis wound on the front and rear wheels. Each of the front wheels includesa periphery and a plurality of recesses defined in the periphery. Eachof the rolling units includes rollers each of which can be received in arelated one of recesses.

Other objectives, advantages and features of the present invention willbe apparent from the following description referring to the attacheddrawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via detailed illustration of twoembodiments referring to the drawings wherein:

FIG. 1 is a perspective view of a treadmill according to the firstembodiment of the present invention;

FIG. 2 is an enlarged perspective view of a front portion of thetreadmill shown in FIG. 1;

FIG. 3 is an enlarged front view of the treadmill shown in FIG. 1;

FIG. 4 is an enlarged perspective view of a rear portion of thetreadmill shown in FIG. 1;

FIG. 5 is an enlarged rear view of the treadmill shown in FIG. 1;

FIG. 6 is a perspective view of a treadmill according to the secondembodiment of the present invention;

FIG. 7 is an enlarged perspective view of a front portion of thetreadmill shown in FIG. 6; and

FIG. 8 is an enlarged front view of the treadmill shown in FIG. 6.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring to FIG. 1, a treadmill includes a frame 10, two front wheels50 supported on the frame 10, two rear wheels 60 also supported on theframe 10, a caterpillar track 20 wound on the front wheels 50 and therear wheels 60, two rolling units 30 each connected to a related one oftwo edges of the caterpillar track 20, and two guiding units 40 each forguiding a related one of the rolling units 30 according to a firstembodiment of the present invention. Although not shown, a motor isconnected to the front wheels 50 so that the motor drives thecaterpillar track 20 through the front wheels 50.

The frame 10 includes three crossbars 11 located between and connectedto two longitudinal bars 12 so that the frame 10 is rectangular. Theframe 10 includes a front end 13 and a rear end 14. The longitudinalbars 12 extend from the front end 13 to the rear end 14. Two pads 15 areattached to a lower surface of each of the longitudinal bars 12 tofacilitate stable positioning of the frame 10 on the ground or a floor.

The caterpillar track 20 includes a plurality of slabs 22 connected toone another by two chains. Each of the chains is connected to a relatedone of the edges of the caterpillar track 20. In detail, each of theslabs 22 includes two pivots each extending from a related one of twoopposite ends. Each of the chains includes a plurality of links 21. Eachof the links 21 includes two apertures each for receiving a related oneof the pivots of a related one of the slabs 22. That is, each of thepivots of each of the slabs 22 is inserted through a related one of theapertures of each of two related links 21.

Each of the rolling units 30 includes a plurality of rollers 31. Each ofthe rollers 31 of each of the rolling units 30 is provided on a relatedone of the pivots of a related one of the slabs 22 and retained there bya nut 23 for example.

Referring to FIG. 2, each of the guiding units 40 includes an upper rail41, an upper cushioning strip 42, a lower rail 43 and a lower cushioningstrip 44. The upper rails 41 and the lower rails 43 are connected to theframe 10.

The upper rail 41 of each of the guiding units 40 includes a groove forreceiving the upper cushioning strip 42 and some of the rollers 31 of arelated one of the rolling units 30. Thus, some of the rollers 31 ofeach of the rolling units 30 are guided by the upper rail 41 of therelated guiding unit 40. The upper cushioning strip 42 of each of theguiding units 40 is attached to the upper rail 41 by adhesion forexample. The upper cushioning strip 42 of each of the guiding units 40is located between the upper rail 41 and the related rollers 31 of therelated rolling unit 30. Thus, there is little vibration or noise whensome of the rollers 31 of each of the rolling units 30 roll on the upperrail 41 of the related guiding unit 40.

Similarly, the lower rail 43 of each of the guiding units 40 includes agroove for receiving the lower cushioning strip 44 and some others ofthe rollers 31 of a related one of the rolling units 30. Thus, some ofthe rollers 31 of each of the rolling units 30 are guided by the rails41 and 43 of a related one of the guiding units 40. The lower cushioningstrip 44 of each of the guiding units 40 is attached to the lower rail43 by adhesion for example. The lower cushioning strip 44 of each of theguiding units 40 is located between the lower rail 43 and the relatedrollers 31 of the related rolling unit 30. Thus, there is littlevibration or noise when some of the rollers 31 of each of the rollingunits 30 roll on the lower rail 43 of the related guiding unit 40.

Referring to FIGS. 2 and 3, the front wheels 50 are supported on a frontaxle 51 connected to the longitudinal bars 12 of the frame 10. The axle51 is connected to the motor, directly or indirectly. Each of the frontwheels 50 includes a plurality of recesses 53 defined in the periphery52, stops 54 each located next to a related one of the recesses 53, andcutouts 55 each defined in a related one of the stops 54. Each of therecesses 53 receives a related one of the rollers 31 and each of thecutouts 55 receives a related one of the nuts 23. The stops 54 of thefront wheels 50 prevent lateral movement of the related rollers 31.

Referring to FIGS. 4 and 5, the rear wheels 60 are supported on a rearaxle 61 supported on the longitudinal bars 12 of the frame 10. Each ofthe rear wheels 60 is supported on the rear axle 61 through a bearing62. Each of the rear wheels 60 includes a stop 64 extending along theperiphery 63. The stops 64 of the rear wheels 60 prevent lateralmovement of the related rollers 31.

Referring to FIGS. 6 through 8, there is shown a treadmill according toa second embodiment of the present invention. The second embodiment islike the first embodiment except two things. Firstly, two rear wheels 50are used instead of the rear wheels 60.

Secondly, each of the front and rear wheels 50 is located in an oppositedirection. Therefore, the cutouts 55 of the front wheels 50 are locatedbetween the recesses 53, and the cutouts 55 of the rear wheels 50 arelocated between the recesses 53.

Thirdly, a shaft 25 is supported on each of two U-shaped elements 24attached to an internal face of each of the slabs 22, with each of theU-shaped elements 24 located near a related one of the opposite ends ofthe slab 22. A ring 32 is supported on each of the shafts 25 before eachof the rollers 31 is supported on a related one of the shafts 25. Eachof the rings 32 is located in a related one of the cutouts 55 while eachof the rings 32 is located in a related one of the recesses 53.

The treadmill of the present invention exhibits several advantages. Atfirst, where the front axle 51 is connected to a motor, the motor stablydrives the caterpillar track 20 via the front wheels 50 because some ofthe rollers 31 are received in some of the recesses 53.

Secondly, no matter whether the front axle 51 is connected to a motor ornot, undesired lateral movement of the caterpillar track 20 between thelongitudinal bars 12 is prevented. That is, smooth operation of thecaterpillar track 20 is ensured.

Thirdly, the operation of the treadmill is peaceful and quiet because ofthe cushioning strips 42 and 44.

The present invention has been described via the detailed illustrationof the embodiments. Those skilled in the art can derive variations fromthe embodiments without departing from the scope of the presentinvention. Therefore, the embodiments shall not limit the scope of thepresent invention defined in the claims.

1. A treadmill including: a frame formed with a front end and a rearend; two front wheels supported on the frame near the front end, whereineach of the front wheels includes a periphery and a plurality ofrecesses defined in the periphery; two rear wheels supported on theframe near the rear end; a caterpillar track wound on the front and rearwheels; and two rolling units each connected to a related one of twoedges of the caterpillar track, wherein each of the rolling unitsincludes rollers each of which can be received in a related one ofrecesses.
 2. The treadmill according to claim 1, wherein each of thefront wheels includes stops each located next to a related one of therecesses for preventing undesired lateral movement of a related one ofthe rollers.
 3. The treadmill according to claim 2, wherein each of thefront wheels includes cutouts each defined in a related one of the stopsfor receiving a reduced extensive portion of each of the slabs.
 4. Thetreadmill according to claim 1, wherein each of the rear wheels includesa periphery and a stop extending along the periphery for preventingundesired lateral movement of a related one of the rollers.
 5. Thetreadmill according to claim 1, further including two guiding units eachfor guiding a related one of the rolling units.
 6. The treadmillaccording to claim 5, wherein each of the guiding units includes upperand lower rails each for guiding some of the rollers.
 7. The treadmillaccording to claim 6, wherein each of the guiding units includes upperand lower cushioning strips respectively attached to the upper and lowerrails for cushioning the related rollers.
 8. The treadmill according toclaim 1, wherein the frame includes a front axle for supporting thefront wheels.
 9. The treadmill according to claim 1, wherein thecaterpillar track includes: a plurality of slabs; and two chains eachincluding links each connected to a related one of two opposite ends ofa related one of the slabs.
 10. The treadmill according to claim 1,wherein the frame includes a rear axle for supporting the rear wheels.11. The treadmill according to claim 10, further including two bearingsfor supporting the rear wheels on the rear axle.